Auto merge of #3048 - lucab:ups/linux-open-tree-flags, r=JohnTitor

linux-like: add OPEN_TREE_CLONE and OPEN_TREE_CLOEXEC

This adds the `OPEN_TREE_CLONE` and `OPEN_TREE_CLOEXEC` constants on Linux and Android.
Those are used by the `open_tree()` syscall and defined in `mount.h`:
 * https://github.com/torvalds/linux/blob/v6.1/include/uapi/linux/mount.h#L61-L65

Author: bors

libc-test/build.rs

@@ -1621,6 +1621,7 @@ fn test_android(target: &str) {
                 "linux/memfd.h",
                 "linux/mempolicy.h",
                 "linux/module.h",
+                "linux/mount.h",
                 "linux/net_tstamp.h",
                 "linux/netfilter/nfnetlink.h",
                 "linux/netfilter/nfnetlink_log.h",
@@ -3197,6 +3198,8 @@ fn test_linux(target: &str) {
         "linux/mempolicy.h",
         "linux/mman.h",
         "linux/module.h",
+        // FIXME: requires kernel headers >= 5.1.
+        [!musl]: "linux/mount.h",
         "linux/net_tstamp.h",
         "linux/netfilter/nfnetlink.h",
         "linux/netfilter/nfnetlink_log.h",
@@ -3402,6 +3405,7 @@ fn test_linux(target: &str) {
                 || name.starts_with("IFLA_")
                 || name.starts_with("MS_")
                 || name.starts_with("MSG_")
+                || name.starts_with("OPEN_TREE_")
                 || name.starts_with("P_")
                 || name.starts_with("PF_")
                 || name.starts_with("RLIMIT_")

libc-test/semver/android.txt

@@ -1648,6 +1648,8 @@ ONLCR
 ONLRET
 ONOCR
 OPENPROM_SUPER_MAGIC
+OPEN_TREE_CLOEXEC
+OPEN_TREE_CLONE
 OPOST
 O_ACCMODE
 O_APPEND

libc-test/semver/linux.txt

@@ -1618,6 +1618,8 @@ NUD_STALE
 OFDEL
 OFILL
 OLCUC
+OPEN_TREE_CLOEXEC
+OPEN_TREE_CLONE
 O_ASYNC
 O_DIRECT
 O_DSYNC

src/unix/linux_like/android/mod.rs

@@ -2121,6 +2121,10 @@ pub const PT_HIOS: u32 = 0x6fffffff;
 pub const PT_LOPROC: u32 = 0x70000000;
 pub const PT_HIPROC: u32 = 0x7fffffff;
 
+// uapi/linux/mount.h
+pub const OPEN_TREE_CLONE: ::c_uint = 0x01;
+pub const OPEN_TREE_CLOEXEC: ::c_uint = O_CLOEXEC as ::c_uint;
+
 // linux/netfilter.h
 pub const NF_DROP: ::c_int = 0;
 pub const NF_ACCEPT: ::c_int = 1;

src/unix/linux_like/linux/mod.rs

@@ -3142,6 +3142,10 @@ pub const IN_ALL_EVENTS: u32 = IN_ACCESS
 pub const IN_CLOEXEC: ::c_int = O_CLOEXEC;
 pub const IN_NONBLOCK: ::c_int = O_NONBLOCK;
 
+// uapi/linux/mount.h
+pub const OPEN_TREE_CLONE: ::c_uint = 0x01;
+pub const OPEN_TREE_CLOEXEC: ::c_uint = O_CLOEXEC as ::c_uint;
+
 // uapi/linux/netfilter/nf_tables.h
 pub const NFT_TABLE_MAXNAMELEN: ::c_int = 256;
 pub const NFT_CHAIN_MAXNAMELEN: ::c_int = 256;